1. Field
Invention relates to computer networks, and in particular to selectively enabling the use of a network-connected computer so that only resources needed for legitimate and authorized use are available.
2. Related Art
A “networked information system” is a collection of computers, together with network communication devices and transmission media that enable the computers to communicate with one another. The limits of a particular system are defined by boundaries that are based on real-world relationships of information technology (IT) asset ownership and operational responsibility. These boundaries are enforced largely by both network-level boundary security mechanisms (firewalls, Virtual Private Networks (VPNs), remote access) and boundary management mechanisms (address management, routing relationships and limitations). Current information technology includes boundary-defining and boundary-enforcing mechanisms that are feasible to use because of relatively simple rules about communication allowed across boundaries. Abuses of the allowed communication capabilities are still possible, via the allowed communication channels. Despite these remaining vulnerabilities, it is still possible to define reasonably simple sets of rules to define the extent of networked system, even if the resulting boundary is sufficiently porous (explicitly allowing various kinds of network access to various kinds of parties not limited to employees) to call into question whether the “boundary” can be described as a “border.”
However, within such boundaries, every non-trivial networked IT system has many actors and objects that are massively multi-inter-related with one another. Almost every network-connected system has potential access of almost every kind to almost every service available with the networked system. Coarse-grained access-control and segmentation can, at best, create sub-systems that are internally massively multi-inter-related, and still highly inter-related to one another.
Even for modest numbers of actors and services, there are large numbers of paths of potential access. Most paths are not intended for use, typically not used, but nevertheless available for abuse or unintentional misuse. Abuse and misuse are particularly troublesome because any one host in a network, if compromised in some way, can spread the effects to many other hosts which can in turn trigger further spread. This high degree of interconnection, and potential for wide and rapid cascading effects, is common to many aspects of IT systems, including security (e.g., malicious software spreading from host to host) to availability (e.g., local performance dysfunction spreading to effect other systems that share a network segment with dysfunctional system).
Accordingly, there is a need to drastically reduce the number of paths that be used at all, and make the use of any such path to be contingent on conditions that can further constrain usage.